Reduction process for preparation of cyclic nitrogen compounds



3,055,882 REDUCTIUN PRUCESS FUR PREPARATION OF CYCLE? NETRQGEN COMPOUNDS Robert Paul Mull, Florham Park, N.J., assignor to Cilia (Torporation, a corporation of Delaware No Drawing. Filed June llll, 1959, Ser. No. 819,209 11 Claims. (Cl. Mil-239) The present invention concerns a process for the preparation of guanidino compounds. More particularly, the procedure of the invention relates to the manufacture of (N,N-alkylene-imino)-lower alkyl-guanidines, in which alkylene contains from four to ten carbon atoms as ring members, and the salts thereof. Also anticipated are quaternary ammonium compounds and acyl derivatives of these compounds, whenever prepared according to the procedure of the invention.

N,N-alkylene-imino radicals, containing from four to ten carbon atoms, primarily from six to eight carbon atoms, are unsubstituted, or may contain as further substituents of carbon atoms lower hydrocarbon radicals, such as lower alkyl, e.g. methyl or ethyl. They may be represented by N,N-tetramethylene-imino (l-pyrrolidino), N,N-pentamethylene-imino (l-piperidino), N,N-hexamethylene-imino (l-hexahydro-azepino), N,N-heptamethylene-imino (l-octahydroazocino), N,N-octamethylene-imino (l-octahydro azonino), N,N-nonamethyleneimino (l-decahydro-azecino) or N,N-decamethyleneimino radicals.

The lower alkyl radical, linking the alkylene-imino ring with the guanidino group, contains from two to seven carbon atoms and is represented by a lower alkylene radical, which may also be branched. Such alkylene radicals contain preferably from two to three carbon atoms and are represented, for example, by 1,2-ethylene, 1-methyl-l,2 ethylene, 2-methyl-l,2-ethylene or 1,3-propylene; additional alkylene radicals are, for example, 2,3- butylene, 1,3-butylene, 1,4-butylene, 1,4-pentylene, 1,5- pentylene and the like.

The guanidino group is preferably unsubstituted. However, the amino, as well as the irnino groups of the guanidino portion may be substituted by lower hydrocarbon radicals, such as lower alkyl, e.g. methyl or ethyl. Such substituted guanidino groups are, for example, N- monomethyl-, N-polymethyl-, N-monoethyl or N-polyethyl-guanidino groups.

Salts of the compounds prepared according to the process of this invention are particularly therapeutically useful acid addition salts, such as those with inorganic acids, for example, hydrohalic acids, e.g. hydrochloric or hydrobromic acid, sulfuric or phosphoric acids, or those with organic acids, such as formic, acetic, propi onic, glycolic, lactic, pyruvic, oxalic, malonic, succinic, maleic, fumaric, malic, tartaric, citric, ascorbic, hydroxymaleic, dihydroxymaleic, benzoic, phenylacetic, 4-aminobenzoic, 4-hydroxybenzoic, anthranilic, cinnamic, mandelic, salicylic, 4- aminosalicylic, Z-phenoxybenzoic, 2- acetoxy-benzoic, methane sulfonic, ethane sulfonic, hydroxyethane sulfonic acid and the like.

The guanidine compounds may also form quaternary ammonium compounds, particularly those with lower alkyl halides, e.gl methyl, ethyl, propyl or isopropyl chloride, bromide or iodide, or lower alkyl lower alkane sulfonates, e.g. methyl or ethyl methane or ethane sulfonate, as well as the corresponding quaternary ammonium hydroxides and the salts which may be formed from the quaternary ammonium hydroxides by the reaction with inorganic acids other than hydrohalic acids or with orgahic acids, such as those outlined above for the preparation of the acid addition salts.

Acyl derivatives of the guanidine compounds prepared according to the procedure of this invention are those 35,655,882 Patented Sept. 25, 1962 acids, e.g. trichloroacetic, hydroxyacetic or cyclopentyl-* propionic acid and the like, or lower alkenoic acids, e.g'.

acrylic acid and the like, with aromatic carboxylic acids;

for example, monocyclic aromatic carboxylic acids, e.g.- benzoic, hydroxybenzoic or aminobenzoic acid and the" like, or bicyclic aromatic carboxylic acids, e.g. l-naph thoic or Z-naphthoic acid and the like, with carbocyclic aryl-lower aliphatic acids, such as monocyclic carbocyclic aryl-lower alkanoic acids, e.g. phenylacetic acid or [3- phenylpropionic acid and the like, or with heterocyclic carboxylic acids, for example, monocyclic heterocyclic carboxylic acids, e.g. nicotinic, isonicotinic or 2-furoic acid and the like.

The above-mentioned derivatives and salts thereof have antihypertensive properties and can be used as antihypertensive agents to relieve hypertensive conditions, particularly neurogenic or renal hypertension. A particular characteristic of this antihypertensive effect is its long duration, which property is especially desirable in the treatment of chronic hypertensive states. Particularly valuable with respect to their long-lasting antihypertensive activity are the (N,N-alkylene-imino)-lower alkylguanidines, in which the N,N-alkyleneimino iportion contains from six to eight, primarily seven, carbon atoms, and carries no additional substituents or only methyl groups, and in which lower alkyl, containing from two to three carbon atoms, separates the N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and their salts with inorganic acids, such as mineral acids, e.g. hydrochloric or sulfuric acid, or with organic acids, such as hydroxy-substituted aliphatic acids, e.g. tartaric or citric acid, or unsaturated aliphatic acids, e.g. maleic acid. This group is represented by the (N,N- heptamethylene-imino)-lower alkyl guanidines, particularly the guanidine compound of the formula:

NH2 U The reduction of the carbonyl portion of the amide groups may be carried out by treatment with an aluminum hydride, particularly an alkali metal aluminum hydride, e.g. lithium aluminum hydride or sodium aluminum hydride, or an earth alkaline metal aluminum hydride, e.g. magnesium aluminum hydride, or aluminum hydride. The reduction with these reagents is preferably performed in the presence of a solvent, particularly an ether, such as a di-lower alkyl ether, e.g. diethyl ether, a lower alkyl carbocyclic aryl ether, e.g. anisole, a di-carbocyclic aryl ether, e.g. diphenyl ether, or a cyclic ether, e.g. tetrahydrofurane or p-dioxane, and, if desired, at an elevated temperature and/or in the atmosphere of an inert gas, e.g. nitrogen.

The desired conversion may also be carried out by electrolytically reducing the amide derivatives on a cathode of a high overpotential such as a cadmium, zinc,

mercury, lead amalgam or lead. The catholyte used in such a reduction is preferably a mixture of water, sulfuric acid and a lower alkanoic acid, e.g. acetic or propionic acid. A platinum, carbon, lead or stainless steel anode may be used; the anolyte is preferably sulfuric acid.

The starting materials used in the above reduction procedure may be prepared, for example, by treating a reactive functional derivative of an (N,N-alkylene-imino)- lower alkyl carboxylic acid or of a guanidino-lower alkyl carboxylic acid with a guanidino or an N,N-alkyleneimine, respectively, to form the desired amide compounds. Reactive derivatives of carboxylic acids are, for example, esters, such as lower alkyl, e.g. methyl or ethyl, esters of activated esters, which are particularly useful for the formation of amide bonds, such as esters with reactive mercaptan compounds, e.g. mercapto-acetic acid, or with reactive hydroxyl compounds, e.g. hydroxy-acetonitrile. Such esters may be prepared according to procedures which are known for the manufacture of analogous esters. Other reactive functional derivatives of acids are the acid addition salts of acid halides, particularly the hydrochloride of an acid chloride, which maybe prepared according to standard methods.

The reaction of these reactive functional derivatives of carboxylic acids with the amino compounds may be carried out, for example, by treating a salt of an acid halide, particularly the hydrochloride of an acid chloride with the amine, preferably in a polar, but non-hydroxylated solvent, such as, for example, dimethylformamide, diethyleneglycol dimethylether, dioxane, tetrahydrofuran and the like.

A modification of the above procedure comprises the converting in (N,N-alkylene-imino)-lower alkyl thiocarboxylic acid guanides or guanidino-lower alkyl thiocarboxylic acid N,N-alkylene-imides, the thiocarbonyl group of the thioarnide portion into a methylene group, and, if desired, carrying out the optional steps.

The replacement of the sulfur in the above-mentioned thioamides may be carried out by desulfurization, for example, with a freshly prepared hydrogenation catalyst, such as Raney nickel, in an alcoholic solvent, e.g. methanol or ethanol, if desired, in the presence of hydrogen, or electrolytically according to the procedure outlined hereinabove for the reduction of the amides.

The thioamides used as the starting materials in this modification may be prepared from the corresponding amides previously mentioned, for example, by treatment with phosphorus trisulfide or phosphorus pentasulfide. A modification may consist in electrolytically reducing the amide in the presence of an alkali metal sulfide, e.g. sodium sulfide, thereby forming the thioamide as a nonisolated intermediate.

Another method to prepare the above described guanidino compounds comprises replacing in (2-R-l-N,N- alkylene-imino)-lower alkyl-guanidines, in which R represents an oxo group of the formula or a thiono group of the formula :8, such group by two hydrogen atoms, and, if desired, carrying out the optional steps.

The above-mentioned oxo and thiono groups form together with the nitrogen atom of the N,N-alkylene-imino portion an amide or a thioamide group. Such groups may be converted into the desired methyleneimino group by the previously described procedures; for example, an oxo group of an amide grouping may be replaced by two hydrogen atoms by treatment with an aluminum hydride, such as lithium aluminum hydride, or a thiono group of a thioamide grouping may be exchanged for two hydrogen atoms by desulfurization with a freshly prepared hydrogenation catalyst, such as Raney nickel. These reactions are carried out as previously shown.

The starting material used in this modification may be prepared, for example, by introducing into a 2-oxo-1- N,N-alkylene-imine an amino-lower alkyl radical, which may be accomplished, for example, by reacting an alkali metal, e.g. lithium or sodium, salt of the 2-oxo-1-N,N-

alkylene-imine with a cyano-lower alkyl-halide, e.g. chloride, and reducing in a resulting (2-oxo-l-l I,N-alkyleneimino)-lower alkyl nitrile the nitrile group to a methyleneamino group, which may be accomplished, for example, by treatment with a hydride, such as an aluminum hydride, e.g. lithium aluminum hydride. The 2-0240-1- N,N-alkylene-imine may also be reacted with a lower alkene-nitrile, e.g. acrylonitrile, to yield the (2-oxo-1-N,N- alkylene-imino)-lower alkyl nitrile, which is then reduced to the desired amino compound as shown hereinabove. The thus obtained (2-ox0-1-N,N-alkylene-imino)-lower alkyl-amine may then be converted to the corresponding guanidine, for example, by treatment with a salt of an S-lower alkyl-isothiourea, such as the S- methyl-isothiourea sulfate.

A resulting (2-oxo-1-N,N-alkylene-imino)-lower alkylguanidine compound may be converted to the (Z-thionol-N,N-alkylene-imino)-lower alkyl-guanidine, for example, by treatment with phosphorus trisulfide or phosphorus pentasulfide as shown hereinbefore.

The above-described starting materials are new and are intended to be included within the scope of this invention. Such compounds are, for example, (N,N-alkyleneimino)-lowcr alkyl carboxylic acid guanides, in which alkylene has the above-given meaning, and salts thereof. A preferred group of compounds are (N,N-alkyleneimino)-lower alkyl carboxylic acid guanides, in which alkylene contains from six to eight carbon atoms, the lower alkyl carboxylic acid portion contains from two to three carbon atoms, separating the N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and the guanidino group ,is otherwise unsubstituted. This preferred group may be represented by the (l-N,N-heptamethylene-imino)-acetic acid guanide. These amide compounds may also be prepared by treating a reactive ester, formed by a hydroxy-lower alkyl carboxylic acid guanide with a strong acid, for example, a hydrohalic acid, e.g. hydrochloric acid, with the N,N- alkylene-imine, if desired, in the form of a salt, such as an alkali metal salt thereof. Such reactive esters are, for example, chloro-lower alkyl carboxylic acid guanides.

Another group of valuable intermediates are the (N,N- alkylene-imino)-lower alkyl thiocarboxylic acid guanides, in which alkylene has the above-given meaning, and salts thereof. These compounds are represented by the group of (N,N-alkylene-imino)-lower alkyl thiocarboxylic acid guanides, in which alkylene contains from six to eight carbon atoms, the lower alkyl thiocarboxylic acid portion contains from two to three carbon atoms, and separates the N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and the guanidino group is otherwise unsubstituted; the (1-N,N-heptamethylene-imino)-thioacetic acid guanide illustrates this preferred group.

Also included are the guanidino-lower alkyl carboxylic acid N,N-alkylene-imides, in which alkylene has the above-given meaning, and salts thereof. This series of intermediates is represented by the preferred group of guanidino-lower alkyl carboxylic acid N,N-alkyleneimides, in which alkylene contains from six to eight carbon atoms, the lower alkyl carboxylic acid portion contains from two to three carbon atoms, separating the N,N- alkylene-imino portion from the guanidino group by the same number of carbon atoms, and the guanidino group is otherwise unsubstituted. The guanidino-acetic acid N,N-heptamethylene-imide represents this preferred group of compounds. These compounds may also be prepared, for example, by treating a guanidine with a reactive ester, formed by a hydroxy-lower alkyl carboxylic acid N-N-alkylene-imide and a strong acid, such as a mineral acid, e.g. hydrochloric acid. Such reactive esters are, for example, chloro-lower alkyl carboxylic acid N,N-lower alkylene-imides.

Furthermore, the above-disclosed guanidino-lower alkyl thiocarboxylic acid N,N-alkylene-imides, in which alkylene has the previously given meaning, and their salts are also part of the present invention. They are represented by the preferred group of guanidino-lower alkyl thiocarboxylic acid N,N-alkylene-imides, in which alkylene contains from six to eight carbon atoms, the lower alkyl thiocarboxylic acid portion contains from two to three carbon atoms, separating the N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and the guanidino group is otherwise unsubstituted, and illustrated, for example, by the guanidino-thioacetic acid l-N,N-heptarnethylene-imide.

The (2-oxo-1-N,N-alkylene-imino)-lower alkyl-guanidines, in which alkylene has the previously given meaning, as well as their salts, represent a further group of valuable intermediates, which may be illustrated by the preferred group of (2-oxo-1-N,N-alkylene-imino)-lower alkyl-guanidines, in which alkylene contains from six to eight carbon atoms, lower alkyl contains from two to three carbon atoms separating the guanidino group from the alkylene-imino portion by two to three carbon atoms, and the guanidino group is otherwise unsubstituted. The 2 (2-oxo-1-'N,N-heptamethylene-imino)-ethyl-guanidine represents one of the preferred members.

Also included are the (2-thiono-1-N,N-alkyleneimino)-lower alkyl guanidines, in which alkylene has the previously given meaning, and the salts thereof. A preferred group of these intermediates are the (Z-t-hiono-l- TN,N-alkylene-imino)-lower alkyl-guanidines, in which allkylene contains from six to eight carbon atoms and lower :alkyl from two to three carbon atoms separating the guanidino group from the alkylene-imino portion by two to three carbon atoms, whereas the guanidino group is otherwise unsubstituted. This group may be represented by the 2-(2-thiono-1-N,N-heptamethylene-imino)-ethyl- .guanidine.

A combination of the two principal modifications of the process of the present invention may also be anticipated. For example, upon treatment of a (Z-oxo-l- ZN,N-alkylene-imino')-lower alkyl carboxylic acid guanide or of a guanidino-lower alkyl-carboxylic acid 2-oxo-1- N,N-alkylene-imide, in which alkylene has the abovegiven meaning, with one of the reduction reagents previously described, the desired (N,N-alkylene-imino)- lower alkyl-guanidines described hereinbefore, may be formed. The starting materials used in such a procedure may be prepared along the previously outline procedures by selecting the appropriate intermediates.

Likewise, (2-thiono-l-N,N-alkylene-imino)-lower alkyl thiocarboxylic acid guanides or guanidino-lower alkyl thiocarboxylic acid 2-thiono-1-N,=N-alkylene-imides may be converted to the desired (N,N-alkylene-imino)-lower alkyl-guanidines, for example, by desulfurization as outlined hereinabove. The above starting materials may be prepared according to the previously outline procedures by selecting the appropriate intermediates.

Depending on the conditions used, the guanidine compounds are obtained in the form of the free compounds or as the Salts thereof. -A salt may be converted into the free compound in the customary way, for example, by treatment with an alkaline reagent, such as an aqueous alkali metal hydroxide, e.g. lithium, sodium or potassium hydroxide, an aqueous alkali metal carbonate, e.g. lithium, sodium or potassium carbonate or hydrogen carbonate, or aqueous ammonia. A free base may be transformed into its therapeutically useful acid addition salts by reaction with an appropriate inorganic or organic acid, such as one of those outlined hereinabove, preferably in the presence of a solvent, such as a lower alkanol, e.g. methanol, ethanol, propanol or isopropanol, or an ether, e.g. diethylether or p-dioxane, and the like.

Acyl derivatives of the guanidine compounds of the present invention may be prepared, for example, by treat ing a resulting guanidine compound with the reactive derivative of a carboxylic acid, for example, with a halide, e.g. chloride, or with the anhydride of a carboxylic acid.

The reaction is preferably carried out in an inert solvent, for example, in a hydrocarbon, such as an aliphatic hydrocarbon, e.g. hexane, or an aromatic hydrocarbon, e.g. benzene, toluene or xylene, or in a tertiary organic base, such as a liquid pyridine compound, e.g. pyridine or collidine.

The guanidine compounds may be converted into the quaternary ammonium compounds by reacting the tertiary bases with an ester formed by a hydroxylated lower hydrocarbon compound with a strong inorganic or or ganic acid. Hydroxylated lower hydrocarbon compounds contain from one to seven carbon atoms and the esters thereof are more especially those with mineral acids, e.g. hydrochloric, hydrobromic, hydriodic, or sulfuric acid. Such esters are specifically lower alkyl halides, e.g. methyl, ethyl or propyl chloride, bromide or iodide, or lower alkyl lower alkane sulfonates, e.g. methyl or ethyl methane or ethane sulfonate. The quaternizing reaction may be performed in the presence or absence of a solvent; suitable solvents are more especially lower alkanols, e.g. methanol, ethanol, propanol, isopropanol, tertiary butanol or pent-anol, lower alkanones, e.g. acetone or ethyl methyl ketone, or organic acid amides, e.g. formamide or dimethylformamide. If necessary, an elevated temperature and/ or a closed vessel may be employed.

The invention also comprises any modification of the general process wherein a compound obtainable as an intermediate at any stage of the process is used as starting material and the remaining steps(s) of the process is (are) carried out, as well as any new intermediates.

In the process of this invention such starting materials are preferably used which lead to final products mentioned in the beginning as preferred embodiments of the invention.

As used herein, the term thiocarboxylic acid (or derivative thereof) refers to a structure in which the sulfur is a thiono sulfur, i.e, double bonded to carbon.

The following examples illustrate the invention and are not to be construed as being limitations thereon. Temperatures are given in degrees centigrade.

Example 1 13.6 g. of chloroa-cetyl guanide is added while stirring to a solution of 22.6 g. of heptamethylene-imine in 200 ml. of benzene. After warming for one hour, and then cooling, the solution is filtered and the filtrate concentrated under reduced pressure.

The residue, containing the 2-('1-N,N-heptamethyleneimino)-acetic acid guanide, i suspended in tetrahydrofurane and added to a refluxing solution of 6 g. of lithium aluminum hydride in tetrahydrofuran. After completion of the reaction, the excess of lithium aluminum hydride is decomposed by adding water, then aqueous sodium hydroxide. The solid material is filtered off, the filtrate is acidified with sulfuric acid and the 2-(1-N,N- heptarnethylene-imino)-ethyl-guanidine sulfate can be recovered and recrystallized from aqueous ethanol, M.P. 276-281 (with decomposition) Example 2 16.6 g. of 3 (2-oxo-1-N,N-hexamethylene-imino)- propionitrile is dissolved in absolute ethanol and hydrogenated over 2 g. of Raney nickel at a temperature of about and under pressure. After the necessary amount of hydrogen is taken up, the solution is cooled and the catalyst removed by filtration. The filtrate is treated with 13.9 g. of S-methyl-isothiourea sulfate; the mixture is refluxed until the evolution of methyl-mercaptan ceases. The solution is concentrated under reduced pressure, the residue is taken into water, aqueous sodium hydroxide is added, and the aqueous layer is extracted with ether.

The ether solution is dried and then added to a solution of 5 g. of lithium aluminum hydride in 500 ml. of ether. The reaction mixture is refluxed overnight, the excess of 7 lithium aluminum hydride is decomposed by adding water and the reaction mixture is filtered. The solvent is evaporated, and the residue, containing the 3-(N,N-hexamethylene-imino)-propyl-guanidine, is converted to the sulfate by adding dilute sulfuric acid and concentrating the aqueous solution.

The starting material may be prepared by slowly adding to a solution of 56.5 g. of caprolactam in 150 ml. of p-dioxane, 28 g. of acrylonitrile while stirring and cooling. A few drops of a strong base, such as benzyl trimethylammonium hydroxide, are added to initiate the reaction, and the temperature is maintained between 30- 35 for one-half hour. The mixture is allowed to stand for several days at room temperature, and is then acidified with hydrochloric acid. The residue, after evaporating the solvent, yields the desired 3-(l-N,N-hexamethyleneimino)-propionitrile by distillation, B.P. l33-l36/ 0.3

What is claimed is:

1. A member selected from the group consisting of (N,N-alkylene-imino)-lower alkyl carboxylic acid guanide, in which alkylene has six to eight carbon atoms, and the lower alkyl carboxylic acid portion has from two to three carbon atoms and separates the N,N-alkyleneimino portion from the guanidino group by two to three carbon atoms, and acid addition salts thereof 2. A member selected from the group consisting of (N,N-alkylene-imino)-lower alkyl thiocarboxylic acid guanide, in which alkylene has six to eight carbon atoms, and the lower alkyl thiocarboxylic acid portion has from two to three carbon atoms and separates the N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and acid-addition salts thereof.

3. A member selected from the group consisting of guanidino-lower alkyl carboxylic acid N,N-alkyleneimide, in which alkylene has six to eight carbon atoms, and the lower alkyl carboxylic acid portion has from two to three carbon atoms and separates the N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and acid-addition salts thereof.

4. A member selected from the group consisting of guanidino-lower alkyl thiocarboxylic acid N,N-alkyleneimide, in which alkylene has six to eight carbon atoms,

and the lower alkyl thiocarboxylic acid portion has fr m two to three carbon atoms and separates the N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and acid-addition salts thereof.

5. (1-N,N-heptamethylene-imino)-acetic acid guanide.

6. (1-N,N-heptamethylene-imino)thioacetic acid guanide.

7. Guanidino acetic acid N,N-heptamethylene-imide.

8. Guam'dino thioacetic acid N,N heptamethyleneimide.

9. A member selected from the group consisting of (2-R-1N,N-alkylene-imino)-lower alkyl-guanidine, in which alkylene has six to eight carbon atoms, R is a member selected from the group consisting of 0x0 of the formula =0 and thiono of the formula :8, and lower alkyl has from two to three carbon atoms and separates the 2-R-l-N,N-alkylene-imino portion from the guanidino group by two to three carbon atoms, and addition salts thereof.

10. 2 (2 oxo 1 N,N heptamethylene imino)- ethyl-guanidine.

11. 2 (2 thiono 1 N,N heptamethylene imino)- ethyl-guanidine.

References Cited in the file of this patent UNITED STATES PATENTS 2,846,382 Allen Aug. 5, 1958 2,852,510 Hoffmann et al Sept. 16, 1958 2,852,528 Hofimann et al Sept. 16, 1958 2,909,523 Bach et al. Oct. 20, 1959 2,957,867 Werner Oct. 25, 1960 FOREIGN PATENTS 874,447 Germany Apr. 23, 1953 OTHER REFERENCES Cook et al.: J. 'Phys. Chem., vol. 36, pp. 2383-89 (1932).

Sidgwick: Organic Chemistary of Nitrogen (1937), pp. 297-298.

Migrdichian: Organic Synthesis, v01. 1, pp. 176-186 (1957). 

1. A MEMBER SELECTED FROM THE GROUP CONSISTING OF (NN-ALKYLEN-IMINO)-LOWER ALKYL CARBOXYLIC ACID GUANIDE, IN WHICH ALKYLENE HAS SIX TO EIGHT CARBION ATOMS, AND THE LOWER ALKYL CARBOXYLIC ACID PORTION HAS FROM TWO TO THREE CARBON ATOMS AND SEPARATES THE N,N-ALKYLENEIMINO PROTION FROM THE GUANIDINO GROUP BY TWO TO THREE CARBON ATOMS, AND ACID ADDITION SALT THEREOF.
 3. A MEMBER SELECTED FROM THE GROUP CONSISTING OF GUANIDINO-LOWER ALKYL CARBOXYLIC ACID N,N-ALKYLENEIMIDE, IN WHICH ALKYLENE HAS SIX TO EIGHT CARBOM ATOMS, AND THE LOWER ALKYL CARBOXYLIC ACID PORTION HAS FROM TWO TO THREE CARBON ATOMS AND SEPARTATES THE N,N-ALKYLENE-IMINO PROTION FROM THE GUANIDINO GROUP BY TWO TO THREE CARBON ATOMS, AND ACID-ADDITION SALT THEREOF.
 5. (1-N,N-HEPTAMETHYLENE-IMINO)-ACETIC ACID GUANIDE.
 9. A MEMBER SELECTED FROM THE GROUP CONSISTING OF (2-R-1-N,N-ALKYLENE-IMIMINO)-LOWER ALKYL -GUANIDINE, IN WHICH ALKYLENE HAS SIX TO EIGHT CARBON ATOMS, R IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF OXO OF THE FORMULA =0 AND THIONIN OF THE FORMULA =S, AND LOWER ALKYL HAS FROM TWO TO THREE CARBON ATOMS AND SEPARATES THE 2-R-1-N,N-ALKYLENE-IMINO PORTING FROM THE GUANIDINO GROUP BY TWO TO THREE CARBON ATOMS, AND ADDITION SALTS THEREOF. 